Untreated mental health problems are among the most disabling, persistent, and costly health conditions.
Because they often begin in childhood and continue into adulthood, there has been growing interest in preventive mental health programs for children.
In recent years, several such programs have been implemented at regional, state, or national scale, and although many experimental studies have documented positive outcomes of individual programs, this article represents the first attempt to systematically compare the largest programs in terms of scope, scale, and dose.